The first officer's experience of the section of the river qualified him to oversee the pilotage training of the second officer. In addition to his supervisory role, the first officer undertook the other duties of the officer in charge of the watch, except for the actual conning of the vessel. For example, he had discussed passing procedures with another vessel and was making log entries. These actions should have allowed the second officer to concentrate on his primary task. However, because the first officer was busy with these other duties, he did not give his full attention to the actions of the second officer when the vessel was approaching the alter-course position. Once he realized that the vessel had passed the course alteration point and advised the second officer to this effect, he did not monitor closely the heading change ordered by the second officer. The first officer's direction to bring the vessel further over did not engender the intended response from the second officer. The second officer's order for a change of heading to 185 was not the full port helm order envisaged by the first officer. Only when the first officer realized that the Bay State Shoal light was too fine on the bow, did he intervene and attempt to correct the situation. When communication is ambiguous, as in the use of the term over, the message is open to misinterpretation. Although the immediate execution of the intended order may not have affected the outcome in this instance because it was given late, the ambiguous nature of such communications has the potential to negatively influence safety.Analysis The first officer's experience of the section of the river qualified him to oversee the pilotage training of the second officer. In addition to his supervisory role, the first officer undertook the other duties of the officer in charge of the watch, except for the actual conning of the vessel. For example, he had discussed passing procedures with another vessel and was making log entries. These actions should have allowed the second officer to concentrate on his primary task. However, because the first officer was busy with these other duties, he did not give his full attention to the actions of the second officer when the vessel was approaching the alter-course position. Once he realized that the vessel had passed the course alteration point and advised the second officer to this effect, he did not monitor closely the heading change ordered by the second officer. The first officer's direction to bring the vessel further over did not engender the intended response from the second officer. The second officer's order for a change of heading to 185 was not the full port helm order envisaged by the first officer. Only when the first officer realized that the Bay State Shoal light was too fine on the bow, did he intervene and attempt to correct the situation. When communication is ambiguous, as in the use of the term over, the message is open to misinterpretation. Although the immediate execution of the intended order may not have affected the outcome in this instance because it was given late, the ambiguous nature of such communications has the potential to negatively influence safety. As part of his pilotage training, the second officer had the con of the vessel under the supervision of the first officer. The second officer did not order the required change of heading at an alter-course position. When the first officer noticed the vessel had overshot the alter-course position, he did not monitor closely the heading change ordered by the second officer. The minor course adjustments ordered by the second officer were insufficient to compensate for the vessel having passed the alter-course position. When the first officer ordered the necessary full helm, there was insufficient time to avert the contact with the bottom. The owners had no documented policy on piloting by ship's officers or pilotage training of ship's officers, and these operations were carried out at the master's discretion.Findings As part of his pilotage training, the second officer had the con of the vessel under the supervision of the first officer. The second officer did not order the required change of heading at an alter-course position. When the first officer noticed the vessel had overshot the alter-course position, he did not monitor closely the heading change ordered by the second officer. The minor course adjustments ordered by the second officer were insufficient to compensate for the vessel having passed the alter-course position. When the first officer ordered the necessary full helm, there was insufficient time to avert the contact with the bottom. The owners had no documented policy on piloting by ship's officers or pilotage training of ship's officers, and these operations were carried out at the master's discretion. The SAUNIRE struck the bottom at Bay State Shoal because the necessary corrective action was not ordered immediately when it was realized that the vessel had passed the alter-course position.Causes and Contributing Factors The SAUNIRE struck the bottom at Bay State Shoal because the necessary corrective action was not ordered immediately when it was realized that the vessel had passed the alter-course position.